Bacterial inhibition and biofilm eradication ability of low-toxic deep eutectic solvents prepared from lactic acid and quaternary ammonium compounds

[Display omitted] •Comparison of antibacterial and cytotoxic properties of LA and two QAC-based DESs.•DESs have antibacterial activity against gram-positive and gram-negative bacteria.•DESs effectively eradicated established bacterial biofilms.•Compared to LA, DESs show lower cytotoxicity towards 3 T3-L1 cells. In the present communication, the preparation of deep eutectic solvents (DESs) based on an aqueous solution of lactic acid (LA) and two different quaternary ammonium compounds, choline chloride (ChCl) and tetraethylammonium chloride (TEAC), is proposed for the application as an antibacterial agent. The antibacterial and cytotoxic properties of the DESs obtained were studied and found to be highly effective in inhibiting both Gram-positive and Gram-negative bacteria and eradicating bacterial biofilms. Moreover, the DESs obtained exhibited reduced cytotoxicity towards soft tissue cells compared to the aqueous LA solution. The excellent antibacterial properties and low cytotoxicity of the DESs prepared make them a promising candidate for the development of novel antimicrobial agents or antibacterial eutectogels for delivery systems and tissue engineering applications.